Here is Phil Lawler’s excellent-as-usual analysis: “Pope broadens access to 1962 Mass (news/analysis)”, as well as his notation of a minor error in the US bishops’ translation.
Fr. Zuhlsdorf gives his initial comments on the document.
Fr. Philip Powell, OP, alerts us to the six stages of dissenting from the motu proprio.
Meanwhile, Fr. Martin Fox gives a parish priest’s eminently sensible view on the document and what it will entail, and almost more important, what it does not do.
I’m sure there are a million and one other excellent reactions out there. I just haven’t got to them yet, but if you’re looking for a place to start—as an alternative to the dreck you’ll read in the secular press—these aren’t bad.